The early lesions of atherosclerosis in youth are strongly related to antemortem levels of total and low-density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, and triglyceride to ponderal index and to blood pressure. The major apolipoproteins of LDL and high-density lipoprotein (HDL), apoB and apoA1 respectively, and levels of Lp(a) lipoprotein are often abnormal in children born in a family with premature coronary artery disease (CAD). Other risk factors for CAD include obesity, high blood pressure, cigarette smoking, diabetes mellitus, positive family history of CAD, and physical inactivity. Children from families with premature CAD, dyslipidemia, or hypertension, and/or two other risk factors should have a lipoprotein profile determined. Treatment begins with a diet low in total fat, saturated fat, and cholesterol, combined with treatment of overnutrition and obesity, if necessary, and regular habits of aerobic physical activity. Children with inherited disorders of LDL metabolism may require the addition of lipid-lowering therapy. The early detection and treatment of youth at risk for premature CAD offer the greatest promise to decrease morbidity and mortality.